_:vb50942985 . _:vb50942985 . _:vb50942985 . _:vb50942985 . _:vb50942985 "A retinitis pigmentosa that has_material_basis_in mutation in the PDE6A gene on chromosome 5q31-q33."^^ . _:vb50942985 . _:vb50942985 "url:https://www.ncbi.nlm.nih.gov/pubmed/7493036"^^ .